High internal inventory levels at Texas Instruments and across the semiconductor industry are making some analysts a bit nervous.

Technology supply chain inventories rose from 37.8 days to 38.2 days in the third quarter — the highest level in four years, RBC Capital Markets semiconductor analyst Doug Freedman in a report today.

Semiconductor companies are running 15 percent above their 5-year inventory average partly and are approaching all-time high inventory levels due to softer sales and a lack of demand, Freedman said. Supply chain growth could slow in the next two quarters to three quarters as inventories remain high, factories are underutilized and the macro growth forecast remains slack, he said.

Dallas-based TI’s inventories fell by $117 million, or 6 percent, in the third quarter from a year earlier and were down $37 million, or 2 percent, from the second quarter. But chief financial officer Kevin March said the decline was mostly due to an accounting change at the company’s National Semiconductor unit.

TI’s customers “are uncertain as to their end demand and they’re carrying as little inventory as they feel they can get away with,” March said last month. As a result, “TI has built up its finished goods inventory in the last quarter” to deliver more just-in-time product to customers, he said.

TI vice president Ron Slaymaker last month said he expected weak demand to continue in the current quarter, with low inventories at original equipment manufacturers.

TI said its inventory days were flat in the third quarter from the previous quarter, reflecting lower expectations for the fourth quarter, Stifel Nicolaus & Co. analyst wrote in a report last month.

Chipmakers with inventories running above their 5-year average by more than 10 percent include Altera, Intel Corp., Peregrine Semiconductor and SanDisk Corp., according to RBC. RBC noted that 15 of the 110 companies it tracks have not yet reported third-quarter earnings.